Ngọc Hà is a ward of Hanoi, the capital municipality of Vietnam, in the Red River Delta. Ngọc Hà was a village forming part of Thăng Long, and was known for flower cultivation. References External l
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x99e008494a69b1a4f40675baa0b7f19acd9e405e7fdecc74e67de59c5c76860b. Chain 2 (Bitcoin): anchored in block 953899 (2026-06-16T06:37:25Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/118c513f-75ef-49e3-bf0e-65ad7cf0d8a6.json and https://artists.proofprofile.net/proofs/artist/118c513f-75ef-49e3-bf0e-65ad7cf0d8a6.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).